This invention relates in general to a method of securing first and second splined members together, such as is done when manufacturing a driveshaft assembly for use in a drive train system. In particular, this invention relates to an improved method of securing an end fitting to a midship tube shaft in such a driveshaft assembly to prevent relative axial movement from occurring therebetween.
Drive train systems are widely used for generating power from a source and for transferring such power from the source to a driven mechanism. Frequently, the source generates rotational power, and such rotational power is transferred from the source to a rotatably driven mechanism. For example, in most land vehicles in use today, an engine/transmission assembly generates rotational power, and such rotational power is transferred from an output shaft of the engine/transmission assembly through a driveshaft assembly to an input shaft of an axle assembly so as to rotatably drive the wheels of the vehicle. To accomplish this, a typical driveshaft assembly includes a hollow cylindrical driveshaft tube having a pair of end fittings, such as a pair of tube yokes, secured to the front and rear ends thereof. The front end fitting forms a portion of a front universal joint that connects the output shaft of the engine/transmission assembly to the front end of the driveshaft tube. Similarly, the rear end fitting forms a portion of a rear universal joint that connects the rear end of the driveshaft tube to the input shaft of the axle assembly. The front and rear universal joints provide a rotational driving connection from the output shaft of the engine/transmission assembly through the driveshaft tube to the input shaft of the axle assembly, while accommodating a limited amount of angular misalignment between the rotational axes of these three shafts.
In some instances, the driveshaft assembly is formed from a hollow cylindrical driveshaft tube having a midship tube shaft secured thereto. The midship tube shaft includes a first end that is adapted to be secured to an end of the driveshaft tube and a second end portion having an externally splined portion provided thereon. The first end of the midship tube shaft is typically connected to the end of the driveshaft tube by welding. A center bearing assembly can be mounted on a central portion of the midship tube shaft located between the first and second end portions. An end yoke can be connected to the second end portion of the midship tube shaft. The end yoke has an internally splined sleeve portion that cooperates with the externally splined second end portion of the midship tube shaft so as to be fixed for rotation therewith.
In some applications, it is desirable to prevent relative axial movement from occurring between the midship tube shaft and the end yoke, notwithstanding the splined connection therebetween. To accomplish this, it is known to provide an external thread on the tip of the second end portion of the midship tube shaft. The threaded tip of the second end portion of the midship tube shaft extends through an opening formed through the end yoke. Then, a nut is threaded onto the threaded tip of the second end portion of the midship tube shaft to retain the end yoke thereon and to prevent relative axial movement from occurring therebetween. Although this structure has been effective, it has been found to be somewhat complicated, expensive, and space consuming. Alternatively, it is known to weld the end yoke directly to the second end portion of the midship tube shaft. However, the use of welding can be undesirable for a variety of reasons. Thus, it would be desirable to provide an improved method of securing an end fitting to a midship tube shaft to prevent relative axial movement therebetween in such a driveshaft assembly.